Soil phosphorus constrains biodiversity across European grasslands

“Nutrient pollution presents a serious threat to biodiversity conservation. In terrestrial ecosystems, the deleterious
effects of nitrogen pollution are increasingly understood and several mitigating environmental policies have been
developed. Compared to nitrogen, the effects of increased phosphorus have received far less attention, although some
studies have indicated that phosphorus pollution may be detrimental for biodiversity as well. On the basis of a dataset
covering 501 grassland plots throughout Europe, we demonstrate that, independent of the level of atmospheric
nitrogen deposition and soil acidity, plant species richness was consistently negatively related to soil phosphorus. We
also identified thresholds in soil phosphorus above which biodiversity appears to remain at a constant low level. Our
results indicate that nutrient management policies biased toward reducing nitrogen pollution will fail to preserve biodiversity.
As soil phosphorus is known to be extremely persistent and we found no evidence for a critical threshold
below which no environmental harm is expected, we suggest that agro-environmental schemes should include grasslands
that are permanently free from phosphorus fertilization.”
(Citaat: Ceulemans, T., Stevens, C.J., et al. Soil phosphorus constrains biodiversity across European grasslands – Global Change Biology 20(2014)12, p.3814-3822)